Learned to live with it in my case (Bianca).
I'm not sure if it was an update that messed it up for me, or the fact that I began frequenting YouTube via Firefox, but I lost my sound too about two months ago. I mention YT because it was quite common for YouTube to completely freeze Firefox and my PC both. Bit better recently, but it still does occur.
ASRock 4CoreDual-SATA2 mainboard here, with ALC888 soundchip. I tried an ALC888 driver with no luck.
My sound, since then has largely been "gone" at bootup. Occasionally, however, for some strange reason it reappears, so I'm using Amarok again tonight.
Thanks for the tip about aumix, helios--I just installed the gfx version, and hopefully this has now fixed it.
I did also note that with both the Daryna live CD and Ubuntu 7.10 live CD the soundchip was detected and it worked properly each time (haven't yet installed either).